Coolant Leak at the Radiator Surge Tank Hose - keywords 6.6 8.1 L18 LLY overflow overheat

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in the PI.

Owners may comment on a coolant leak. Upon inspection of the vehicle, it may be found that the coolant surge tank hose has come off at the radiator. The surge tank hose is connected to the radiator by a quick connect fitting. This quick connect fitting is held onto the hose by a round crimp ring. If this crimp ring was not crimped correctly during assembly of the hose, the quick connect fitting may not be held onto the hose securely. When the coolant system builds pressure, it could blow the hose off the quick connect fitting. When this occurs, the quick connect fitting will remain on the radiator and the crimp ring will remain on the hose.

To correct this concern, replace the surge tank hose assembly. If the hose is not readily available, an alternate repair can be made as follows:

1. Remove the crimp ring off the surge tank hose.
2. Remove the quick connect fitting from the radiator.
3. Install a #10 worm style hose clamp, GM part numbers 15628035, 798559 or equivalent in place of the crimp ring.
4. Install the quick connect fitting into the surge tank hose.

Important: The quick connect insert must orientated to ensure a proper connection. The two half moon imprints/tabs on the outer face of the quick connect fitting must be parallel to the long length of the hose.

5. Tighten down the worm style hose clamp to 20-24 in lb or 2.26-2.71 Nm.
6. Reinstall surge tank hose assembly to radiator.

Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.